Conventional quick cooking pastas are produced by preparing pastas either in precooked, high moisture form (containing 55-70% moisture) or in dehydrated form (containing 5-12% moisture) with a thin or expanded structure for quicker rehydration in boiling water. The precooked, high moisture pasta has a poor shelf-life stability which is usually overcome by acidification and in-package pasteurization, while the dehydrated pasta has unsatisfactory textural quality.
Regular semi-moist pasta has a moisture content of about 15-45% and it has the advantage over dehydrated pasta that it requires only about half the cooking time even though the difference in moisture content is not great. The longer cooking time of the dehydrated pasta is due the hardening of the pasta surface of the dehydrated pasta during the drying step. In addition, semi-moist pasta has the advantage over high moisture pasta in that it is easier to preserve. Because of these two advantages, semi-moist pasta can be a convenient quick cooking product provided it has an extended shelf life.
The addition of salt and other humectants to the dough mix to preserve semi-moist pasta products has been described in the prior art. For example, U.S. Pat. No. 4,529,609 describes a method of preserving a semi-moist pasta by dispersing a finely divided salt throughout a dough, partially gelatinizing the salt-containing dough, then drying the gelatinized dough to a moisture content of at least 15% and a maximum water activity of 0.85. However, this patent states that if the product is packaged in a shelf stable form, a preservative should be included in the dough. U.S. Pat. No. 5,573,796 describes a method of producing a fresh pasta product (30-32% moisture) having an extended shelf life by incorporating up to 4% salt in the dough. Although adding salt to the dough is effective in preserving the pasta, it has the disadvantages of imparting a salty taste, and impairing the pasta texture.
We have found that by incorporating sodium chloride and/or another humectant into a dough to obtain a maximum water activity of 0.89 and an alkali to increase the pH to about 11.5, a shelf stable semi moist pasta or pet food is produced without including a preservative in the dough. The moisture content should be from about 15-28%.